The present invention relates to the field of train equipment, and, more particularly, to railway braking and throttle control equipment and associated methods.
Trains are widely used to transport people and freight. Freight trains in particular may be relatively long and include several groups of locomotives (consists). For example, a freight train may be a mile long or more. Coordination is required for operating the locomotives to ensure proper traction and braking, for example.
U.S. Pat. Nos. 4,582,280 and 4,553,723 to Nichols et al. are seminal patents directed to a radio communication based train control system. The radio communication system is for a lead unit and a plurality of remote units. The system includes a protocol for establishing a communication link between the lead unit and the one or more remote units. The protocol prevents any of the units in the system from processing messages or commands from other units in other train systems or processing messages or commands originating from units with the train system but which are addressed to other units. A communications channel contention feature is provided for minimizing the probability of multiple units within the system from transmitting on the common communications channel at the same time. In addition, the system insures that the highest priority communications are transmitted first in time. The control system provides for the coordinated control of the air braking functions in the train.
More recently New York Air Brake Corporation has offered its CCB (II) electronic air brake equipment (EAB) for train and locomotive air brakes with an interface to the control computer (ILC). Such equipment is further described in U.S. Pat. No. 5,172,316 to Root et al.
Another application of computer based control systems relates to so-called xe2x80x9cdistributed powerxe2x80x9d (DP) functions. Such distributed power functions typically control locomotive tractive effort and dynamic braking as well as air brakes. In particular, GE HARRIS Railway Electronics, L.L.C. offers a radio based control system under the designation LOCOTROL(copyright) which provides coordinated distributed power and air brake control of the remote locomotives from the lead locomotive. The system controls tractive effort and braking effort for up to four consists for all types of freight over all types of terrain. Each equipped unit can be operated as a lead or a remote unit.
In the past, two separate control systems were needed and used for the distributed power (DP) and electronic air brake (EAB) functions on a locomotive. These separate control systems had separate processors for each function.
The level of sophistication of the control systems found on locomotives has also been increasing. Today many locomotives include a control computer with standard system and operator interfaces for the distributed power and electronic air brake controls. Locomotives with the control computer and standard interface are generally termed LSI (Locomotive System Integration) compliant and the computer is typically referred to as the integrated locomotive computer (ILC). The locomotive control computer interfaces separately to the two subsystems (EAB and DP) for each function.
Unfortunately, the present approach of two separate processors and subsystems for the distributed power and electronic air brake functions, requires a relatively large amount of precious space within the locomotive. In addition, although conventional systems have a high reliability, certain failures can still render the train inoperable.
Although many modern locomotives include the updated ILC control computer, existing and some new locomotives do not. To control distributed power and electronic air brake functions in such non-LSI compliant locomotives, control must be achieved using the locomotive.
In view of the foregoing background, it is therefore an object of the present invention to provide a railway control system for both distributed power and electronic air brake functions having a high reliability and consuming less space.
It is another object of the invention to provide such a control system that may be selectively used on either LSI compliant or non-LSI compliant locomotives.
These and other objects, features and advantages in accordance with the present invention are provided by a control system comprising a train control system for a train comprising a plurality of locomotives and an air brake system. Each locomotive preferably comprises a locomotive control computer. The train control system includes a plurality of control subsystems for installation in respective locomotives. At least one of the control subsystems is configurable as a lead control subsystem, and at least one other control subsystem is configurable as a remote control subsystem. Each control subsystem preferably comprises one or more radio transceivers, a first processor connected to the radio transceiver for communicating with at least one other control subsystem on another locomotive, an electronic brake valve connected to the first processor, and an electro-pneumatic controller connected to the first processor for interfacing to the air brake system of the train.
Moreover, the first processor preferably comprises a locomotive computer interface for performing both distributed power and electronic air brake functions in cooperation with the locomotive control computer. The distributed power functions may comprise at least one of tractive effort functions, dynamic braking and air brake functions. The electronic air brake functions preferably comprise at least one of automatic service braking, independent braking, and emergency braking. Accordingly, the size of the subsystem is reduced compared to separate distributed power and electronic air brake systems. In addition, reliability is increased.
Each control subsystem also preferably further comprises at least one other processor associated with one of the electronic brake valve and the electro-pneumatic controller and operatively connected to the first processor. In one embodiment, both the electronic brake valve and electro-pneumatic controller include at least one processor. In accordance with another advantageous feature of the invention, the first processor and the at least one other processor comprise distributed processing means for providing a distributed control network. The distributed processing means provide for detection, isolation and response to failures. Thus, reliability is also increased by the distributed control network defined by the multiple processors of the respective devices.
Each control subsystem may further include a trainline drive/sense interface for electrical interfacing on non-LSI compliant locomotives. In addition, each control subsystem may further comprise an antenna connected to the transceiver.
The first processor preferably further comprises status information means for communicating status information when configured as a remote control subsystem. Similarly, the first processor further comprises command information means for communicating command information when configured as a lead control subsystem. Each subsystem is preferably configurable as either a lead or remote control subsystem.
The first processor may comprise means for deselecting distributed power control function. In other words, the control subsystem in some applications may be operated to only use the electronic air brake control functions.
Each control subsystem may further comprise a first housing containing the first processor. In addition, the electronic brake valve may include a second housing, and the electro-pneumatic controller may include a third housing.
A method aspect of the invention is directed to a train control method for a train comprising a plurality of locomotives and an air brake system. Each locomotive also preferably includes a locomotive control computer. The train control method preferably comprises the steps of: installing a plurality of control subsystems in respective locomotives; configuring at least one of the control subsystems as a lead control subsystem; and configuring at least one other control subsystem as a remote control subsystem. Each control subsystem preferably comprises a radio transceiver, a first processor connected to the radio transceiver for communicating with at least one other control subsystem, an electronic brake valve connected to the first processor, and an electro-pneumatic controller connected to the first processor, for interfacing to the air brake system of the train. The first processor preferably comprises a locomotive computer interface for performing both distributed power and electronic air brake functions in cooperation with the locomotive control computer.